1. Field of the Invention
This invention relates in general to the field of laying and setting marble, stone, ceramic, porcelain or other such materials or tiles on floors and in particular to methods and apparatus setting and laying marble tiles or other natural stone of any type, on a floor using relatively unskilled tile layers and producing a finished floor is less time and with greater accuracy.
2. Description of the Prior Art
Marble tile flooring is perhaps the most beautiful, diversified, and costly type of flooring that can be laid in homes, hotels offices, exhibition halls and any other place where a premium floor is desired. Marble tile, is of course a natural product found in many different parts of the world. The variations are numerous, even from the same quarry. The physical properties of marble tile are likewise varied, some are soft, some are hard, some are very fragile being subject to cracking along natural lines. The latter type are sometimes reinforced with a mesh backing.
There are other types of natural stone flooring such as coral, limestone, granite and the like. These like marble tiles have different physical properties and of course present a different effect when installed. One problem that exists with natural flooring products of the type described is the consistency of the thickness and squareness of the tiles in that they are cut from slabs and mechanically finished (In lieu of ceramic tiles which are usually cast from a powered or liquid material and then fired for hardness. Ceramic tiles are usually of a more consistent in thickness but vary in flatness and squareness due to the vagaries of firing the raw product.)
The laying and setting of natural floor tiles of any type, including but not limited to marble tile and other natural stone products or tiles, (hereinafter collectively referred to as “marble tiles”) that have been made into squares, rectangles or other geometric shapes intended for flooring requires precision and very time consuming labor due primarily to the above mentioned physical variations. Other factors also come into play, for example, the base, floor or sub surface on which the marble tile is to be laid must be very level or flat. A non flat surface can result in cracking of the marble tile after it is permanently laid, and of course variations in the flatness of the finished flooring results in an unfavorable aesthetic effect. One prior art solution is to achieve a flat subsurface is by first laying a type of cement backer board on the entire floor. Another type of prior art solution is to attempt to grind the floor to achieve the required degree of flatness. However, the most common prior art method of achieving a level sub floor is to use a relatively thick base usually comprising a layer of adhesive material, a layer of cement based material (known in the trade as “mud”) under each tile and another layer of adhesive material. The adhesive material is usually a product known in the industry as “thin set” which includes cement, sometimes sand, and additives so that a strong bond is achieved between the stone and the mud, and between the mud and the floor. The thick layer of mud is necessary to assure a level floor and to serve as a platform for contraction and expansion and long time stability. The layer of mud can often be between one to three inches in thickness on any given subsurface, which mud is then compressed to a degree necessary such that the upper surface each adjacent tile lies in substantially the same plane. The layers of the thin set are usually about one eight of an inch each. Thus, because floors are not perfectly flat and level and the tiles themselves can vary in thickness, the thickness of the mud necessarily varies in order to assure that the finished stone surfacing is level and flat. For purposes of the description that follows, the combination of the thin set, adhesive, additives, and mud will simply be termed “mud” hereinafter.
In view of the above aspects of marble tile flooring that require or advantageously use a mud base, in the past, a great amount of experience, skill and, know how is required to know how much mud to use at any given sub floor location so that the resulting flooring has taken into account the level variations of the sub floor. Then too, a great amount of time is required to lay and set each adjacent piece of tile or stone so that each piece is perfectly level, flat and aligned with all of the other marble tile tiles or stones making up the finished flooring. In the past then, it is understandable that experienced and extremely time consuming hand labor is involved in laying and setting marble tile flooring. A floor extending over a large area compounds the time and experience and costs needed to achieve a substantially level and aligned marble tile floor.
Thus, there exists the need for methods and apparatus to accomplish efficient but proper laying and setting of marble tile flooring having a mud base without the skill, experience, know how, and hand labor previously required. The present invention fulfills this need.